Improvement in kilns for drying lumber



is. n.1mY. Kilns .fm` Dryingw` Lumber.. N0, 143,912, l 4 PatentedOct. 21,1873.

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. f or NEW YORK, iv. Y.

IMPROVEMENT iN KILNS? FOR DRVING LUMBER.

Specication forming part ofvLetters Patent No. 143,912, dated October 21, 1873; application filed August 11, 1873.

To all whomft may concern:

Be it known that I, STEPHEN R. KIREY, of Detroit, in the county of Wayne and State of Michigan, have invented an Improvement in Kilns for Drying Lumber, of which the following is a specification:

The iirstpart of this invention relates to an improvement in the construction of` that class of kilns for drying lumber wherein the heated airis admitted to the chambers at the top, and exhausted through iiues at the loor. The second part of the inventionl relates to the mea-ns employed for keeping up the temperature of th'e blast after it has left the blower, until the point vor points of delivery are reached. The invention consists in the peculiar construction and arrangement of a heater for raising the temperature of a large volume of airin a blower for forcing the blast to the kilns, constructed in the manner more fully hereinafter described, and in inclosing the exhaust-steam pipe in the air-trunk, which distributes and delivers the blast. 1 y v Figure 1 is a sectional plan lview of a pair of dry-kihls fitted with my improved heater and blast apparatus. Fig. 2 is a longitudinal vertical section at a: in Fig 1. Fig. 3 is a cross-section of the heater and casing at y y,

Fig. 1.

Like letters refer to like parts in the several figures.

In the drawing, A represents a cylindrical shell ttedwitli numerous tubes lying on suitable supports in a horizontal position. Bis a pipe conveying exhaust steam from an engine into one end of the heater A. C is the exhaustpipe, issuing from the other end of the heater. l) is a casingA surrounding the heater, and is open at one end, the otherterminating in a cone emptying into the side opening of a blast-fan, E, which delivers its blast through a trunk, F. The `exhaust-pipe ,C is led from the heater into the trunk; or may be passed through the cone and heater into the trunk,V

extending beyond its terminus for the purpose of sustaining the temperature of the blast, which would otherwise be lowered by radiation and convection.. At Fthe triuik is branched to extend across the dry-kilns G G just under the apex of their roofs, where each side of each trunk `is perforated with openings a, the area of whose discharge may be regulated or shut off entirely by a perforated valve-plate, I), fitted in slides on the side of the trunk.` The walls of the dry-kilns are double, the sp ace between them being filled with sawdustor some other non-conductor. One end wall of each dry-kiln is hinged at the top to form a door; and through the cha-mber is laid a pair of iron-faced rails, H H, in the surface of which are journaled rollers c. At each side of the chamber ues I I extend from the bottom up through the roof, with a valve-plate, b', fitted in slides to regulate the emission of the vapor-laden air-currents.

The lumber to be dried is piled crosswise of v the track upon skids laid longitudinally upon the rollers c, about two thousand square feet being piled on each of two pairs of skids, and pushed into the kiln, and the end door closed,

' when the blast may be turned on by opening a gate, d, in the branch F of the trunk. The air for the blast is drawn by the fan through the tubes of. the heater, and between the heater and its casing, being heated by the exhaust steam passing through the former. The fan drives the blast through the trunk to the drying-chambers, where it comes into contact with the green lumber, which liberates its moisture, which is absorbed by the rarefied air, rendering the latter heavier, and causing it to settle to the iioor, whence it is drawn up and out of the chambers by the exhaust-fines.

The blast, being continuous, soon evaporates the liquids contained in the cells of the timber, and thus dries the lumber without checking or warping it.

These kilns are more especially adapted for lumber 4 mills and wood working establishments, whose exhaust steam is thus rendered available; and are not liable to take tire from overlieat-ing, as is the case where stoves or live steam are used.

The range of kilns in two rows, as described, may be continued or enlarged so as to absorb and utilize the entire volume of exhaust steam, andthe temperature of the blast be kept up to the end of the trunk by carrying the exhaustpipe through it. This gives the present ai'.d

rangement a great advantage over any range of kilns Whose blast-trunk is of any considera-A ble length, and is arranged in the usual manner.

I am aware that tubular heaters and blastfans have been combined for the purpose of heating and. forcing a volume of air through a blast-trunk to a drying kiln or chamber; and, While I disclaim,broadly, the invention of such- What Ido claim as my invention, and desire to secure by Letters Patent, is

l. The arrangement of the exhauststeam pipe C within the blast-trunk F, and with relation to the blast-fan E, tubular heater A,and easing'D, substantially as and for the purpose set forth.

2. The combination of the blastftrunk F, the kilns G G, in pairs, the trammels F', F', gates d d, ues I, and. valve-plates b b, all oonstructed. and arranged substantially as described-and shown, for the purpose set forth.

STEPHEN R. KIRBY.

Witnesses H. F. EBERTs,

H. S. SPRAGUE. 

